move typed headers and implement FromRequest

[ibraheemdev]

PR Type

Refactor

PR Checklist

• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• A changelog entry has been made for the appropriate packages.
• Format code with the latest stable rustfmt.
• (Team) Label with affected crates and semver status.

Overview

• Move common typed headers from actix-http into actix-web.
• Add a Header extractor.
• Refactor awc::TestResponse to use IntoHeaderPair. This is needed now that the typed headers have been moved from -http.

Closes #1837.

[robjtede]

low langing fruit

not delved in too deep yet, but are the parsing functions (from_one_raw_str etc) still part of -http?

[ibraheemdev]

@robjtede I moved the parsing (from_one_raw_str) functions into -web as they were only used once in -http (for ContentEncoding). I can easily change it if you want though.

[robjtede]

My thoughts are just that common parsing and formatting functions still belong in -http as long as their inputs or return types are std or HeaderValue or Vec<HeaderValue> etc.

[ibraheemdev]

So which headers from shared should be moved into -web?

[robjtede]

So which headers from shared should be moved into -web?

i get the impression entity tag is the only one that could move

[robjtede]

great. i think this is in a state to get merged after CI passes

[lovasoa]

Great ! Thank you for implementing this !